The Wolff Integrating Motor Pneumotachograph was utilized to determine oxygen consumption of men traveling on foot, on snowshoes or on skis. As expected, the energy cost of walking in unbroken snow was greater than that of any other activity studied. The advantage of wearing snowshoes in deep snow varied greatly, evidently according to the skill of the wearer. The authors concluded that when the subject is wearing skis, the most efficient speed for covering a long distance is best determined by the subject himself, since caloric cost is approximately independent of speed within a reasonable range of speeds.